To prevent an intranet from outer attacks in a wide area network, an enterprise will deploy security equipment, such as a mandatory firewall. Such security equipment is generally configured to block TCP traffic on all ports except for well-known entry points. Limiting traffic to a limited number of well-known ports makes deploying an application by using non well-known ports complicated or even impossible due to the presence of firewall or other personal firewalls. What's worse, if the network applications open many different unknown ports for inbound connections or different network applications support different network protocols, administrators may need to configure the network security equipment to permit these connections through, which also exposes critical servers to risks and pose greater risks for application deployment in a cloud environment.